The present invention relates to a method and an equipment for enabling versatile charging in telecommunications systems and especially more versatile charging for prepaid subscribers. A prepaid subscriber refers to a subscriber using prepaid subscription, i.e. a subscriber who has paid in advance.
In mobile telecommunications systems, such as the pan-European digital mobile communications system GSM (Global System for Mobile Communications), call prices depend usually on the time when the call is made. To be able to offer more versatile charging possibilities some operators offer prepaid service for subscribers. A prepaid service is a service where a subscriber pays in advance his calls by buying vouchers. The prepaid service logic and prepaid service data are stored in the system. A prepaid SIM (Subscriber Identity Module) card comprises an MSISDN number which is associated with the prepaid service data, including the subscriber's credit, in the system. A prepaid service allows payment of a telephone bill in advance or setting an upper limit for the telephone bills. As another benefit, the prepaid service enable roaming subscribers to pay their local calls at local tariffs, whereas the use of the SIM card of their home service provider results in paying international tariffs to their home network and back.
Usually a prepaid subscription is activated and money added to subscriber's prepaid account by means of vouchers. Some of the service providers sell different types of vouchers, which differ from each other e.g. in the number of call units and the time the call time bought is valid. However, the calls are charged in the same way regardless of what kind of a voucher is used.
The above described possibilities for charging calls are insufficient, since the needs of mobile subscribers and their use of their mobile stations are becoming more and more differentiated. There are users making lot of calls during office hours whereas some other users call seldom and during evenings, for example. The charging of calls has to be diversified correspondingly.